Method and System for Wirelessly Transmitting Data

ABSTRACT

Methods and systems for wirelessly transmitting data between Wi-Fi stations without requiring the Wi-Fi stations to be fully connected to the Wi-Fi network. A first Wi-Fi station generates the data to be transmitted. The data comprises status data and/or wake-up data. The first Wi-Fi station then inserts the data in a vendor-specific information element of a probe request frame and wirelessly transmits the probe request frame. The probe request frame is then received by a second Wi-Fi station. If the probe request frame contains wake-up data and the second Wi-Fi station is operating in a low-power mode when it receives the probe request frame, the second Wi-Fi station will wake-up from the low-power mode. If the probe request frame contains status data then the second Wi-Fi station may process the probe request frame and/or forward at least a portion of the received probe request frame to another device.

BACKGROUND

For a Wi-Fi station to send data within a Wi-Fi network, the stationmust obtain a unique address, namely an IP address from a Wi-Fi accesspoint. To keep the IP address and channel alive, the station must bevalidly connected to the network which requires the station's Wi-Fimodule to be powered on. This inherently consumes more power than if theWi-Fi module is turned off or is in another lower power mode.

Known solutions to this are to keep the Wi-Fi module on in a low-powerstate by extending the Wi-Fi Beacon dwell time or to take the device offthe network (powering down the Wi-Fi module) and then restarting thenetwork connection when needed.

The embodiments described below are not limited to implementations whichsolve any or all of the disadvantages of known systems.

SUMMARY

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

Described herein are methods and systems for wirelessly transmittingdata between Wi-Fi stations without requiring the Wi-Fi stations to befully connected to the Wi-Fi network. A first Wi-Fi station generatesthe data to be transmitted. The data comprises status data and/orwake-up data. The first Wi-Fi station then inserts the data in avendor-specific information element of a probe request frame andwirelessly transmits the probe request frame. The probe request frame isthen received by a second Wi-Fi station. If the probe request framecontains wake-up data and the second Wi-Fi station is operating in alow-power mode when it receives the probe request frame, the secondWi-Fi station will wake-up from the low-power mode. If the probe requestframe contains status data then the second Wi-Fi station may process theprobe request frame and/or forward at least a portion of the receivedprobe request frame to another device.

A first aspect provides a method to wirelessly transmit data, the methodcomprising: generating at a first Wi-Fi station data to be transmittedto another Wi-Fi station, the data comprising at least one of statusdata and wake-up data; inserting at the first Wi-Fi station thegenerated data in a vendor-specific information element of a proberequest frame; and wirelessly transmitting at the first Wi-Fi stationthe probe request frame.

A second aspect provides a Wi-Fi station to wirelessly transmit data,the Wi-Fi station comprising: a processor configured to: generate datato be transmitted to another Wi-Fi station, the data comprising at leastone of status data and wake-up data; and insert the generated data in avendor-specific information element of a probe request frame; and aWi-Fi module configured to wirelessly transmit the probe request frame.

A third aspect provides a system to wirelessly transmit information, thesystem comprising: a first Wi-Fi station, the first Wi-Fi stationcomprising: a processor configured to: generate data to be transmittedto another Wi-Fi station, the data comprising at least one of statusdata and wake-up data; and insert the generated data in avendor-specific information element of a probe request frame; and aWi-Fi module configured to wirelessly transmit the probe request frame;and a second Wi-Fi station configured to: receive the probe requestframe; and execute one or more actions upon receiving the probe requestframe.

A fourth aspect provides a method for waking up a Wi-Fi station from alow-power mode, the method comprising: operating the Wi-Fi station in alow-power mode; receiving at the Wi-Fi station a probe request frame;determining whether the received probe request frame comprises avendor-specific information element comprising wake-up data; if theprobe request frame comprises the vendor specific information elementcomprising wake-up data, waking up the Wi-Fi station from the low-powermode.

A fifth aspect provides a Wi-Fi station comprising: a Wi-Fi moduleconfigured to wirelessly receive a probe request frame; and a processorconfigured to: operate the Wi-Fi device in a low power-mode; determinewhether the received probe request frame comprises a vendor-specificinformation element comprising wake-up data; and if the probe requestframe comprises the vendor specific information element comprisingwake-up data, wake-up the Wi-Fi station from the low-power mode.

The methods described herein may be performed by a computer configuredwith software in machine readable form stored on a tangible storagemedium e.g. in the form of a computer program comprising computerprogram code for configuring a computer to perform the constituentportions of described methods. Examples of tangible (or non-transitory)storage media include disks, thumb drives, memory cards etc. and do notinclude propagated signals. The software can be suitable for executionon a parallel processor or a serial processor such that the method stepsmay be carried out in any suitable order, or simultaneously.

This acknowledges that firmware and software can be valuable, separatelytradable commodities. It is intended to encompass software, which runson or controls “dumb” or standard hardware, to carry out the desiredfunctions. It is also intended to encompass software which “describes”or defines the configuration of hardware, such as HDL (hardwaredescription language) software, as is used for designing silicon chips,or for configuring universal programmable chips, to carry out desiredfunctions.

The preferred features may be combined as appropriate, as would beapparent to a skilled person, and may be combined with any of theaspects of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will be described, by way of example, withreference to the following drawings, in which:

FIG. 1a is a schematic diagram of an IEEE 802.11 management frame;

FIG. 1b is a schematic diagram of the frame body of a probe requestframe;

FIG. 1c is a schematic diagram of a generic information element of FIG.1 b;

FIG. 1d is a schematic diagram of the vendor-specific informationelement of FIG. 1 b;

FIG. 2 is a block diagram of a system for using the vendor-specificinformation element of FIGS. 1b and 1d to instruct a Wi-Fi station to“wake-up” from a low-power mode;

FIG. 3 is a flowchart of a method for causing the low-power Wi-Fistation of FIG. 2 to “wake-up” from a low-power mode;

FIG. 4 is a flowchart of a method for the trigger Wi-Fi station of FIG.2 to generate and transmit a wake-up probe request;

FIG. 5 is a flowchart of a method for the Non-Wi-Fi trigger device ofFIG. 2 to trigger generation and transmission of a wake-up proberequest;

FIG. 6 is a schematic diagram of an exemplary wake-up probe requestframe;

FIG. 7 is a block diagram of a system for sending status data via aprobe request;

FIG. 8 is a flowchart of a method for the status generating Wi-Fistation of FIG. 7 to generate a status probe request;

FIG. 9 is a flowchart of a method for a status receiving Wi-Fi stationof FIG. 7 to process a status probe request; and

FIG. 10 is a schematic diagram of an exemplary status probe requestframe.

Common reference numerals are used throughout the figures to indicatesimilar features.

DETAILED DESCRIPTION

Embodiments of the present invention are described below by way ofexample only. These examples represent the best ways of putting theinvention into practice that are currently known to the Applicantalthough they are not the only ways in which this could be achieved. Thedescription sets forth the functions of the example and the sequence ofsteps for constructing and operating the example. However, the same orequivalent functions and sequences may be accomplished by differentexamples.

The term “Wi-Fi network” is used herein to mean a wireless local areanetwork that is based on the Institute of Electrical and ElectronicsEngineers (IEEE) 802.11 standards. The term “Wi-Fi station” is usedherein to mean an electronic device that has a Wi-Fi module that allowsthe device to exchange data wirelessly using the IEEE 802.11 standards.

Embodiments described herein relate to methods and systems for using thevendor-specific information element in a probe request frame to receiveand/or send data to/from Wi-Fi stations without requiring the Wi-Fistations to be fully connected to the Wi-Fi network (e.g. the stationdoes not require a valid IP address).

When a Wi-Fi station wants to join a Wi-Fi network it either performspassive or active scanning to determine what networks are within rangeof the device. In passive scanning, the station listens for beaconframes from access points. Since access points typically only sendbeacon frames every 100 ms it may take up to 100 ms to receive aperiodic beacon broadcast. In active scanning, the station transmits aprobe request frame and then waits to hear any probe responses orperiodic beacons.

The probe request frame may be either directed or broadcast. A directedprobe request contains a specific Service Set Identifier (SSID) and onlyaccess points with a matching SSID will respond with a probe response.As is known to those of skill in the art an SSID is a sequence ofalphanumeric characters (letters or numbers) that uniquely defines aWi-Fi network. All access points and stations attempting to connect to aspecific Wi-Fi network use the same SSID. A broadcast probe requestcontains a broadcast SSID (a null SSID) and all access points receivingthe probe request will respond with a probe response for each SSID theysupport. The station then processes the received probe responses todetermine which access point to associate with.

IEEE 802.11 management frames enable stations to establish and maintaincommunications. To ensure that all access points and stations in a Wi-Finetwork can properly identify management frames they have a standardframe format shown in FIG. 1a . Specifically, each management frame 100comprises a MAC (Media Access Control) header portion 102, a frame bodyportion 104, and a frame control portion 106. The MAC header portion 102comprises a frame control field 108, a duration field 110, a destinationaddress field 112, a source address field 114, a Basic Service SetIdentification (BSSID) field 116, and a sequence control field 118. Asis known to those of skill in the art a single access point togetherwith all associated stations is called a Basis Service Set (BSS). Theaccess point acts as master to the stations within that BSS. Each BSS isidentified by a BSSID. In an infrastructure BSS, the BSSID is the MACaddress of the access point.

A probe request frame is a specific sub-type of management frame thus ithas the basic frame format shown in FIG. 1a . The difference betweenprobe request frames and other management frames is the format of theframe body portion 104. According to the IEEE 802.11 standard, the framebody portion 104 of a probe request frame has the format shown in FIG.1b . Specifically, the frame body portion 104 of a probe requestcomprises one or more information elements. According to the IEEE 802.11standard, a probe request must comprise an SSID information element 120and a supported rates information element 122.

The SSID information element 120 is used to identify an SSID. When theprobe request is a directed probe request the SSID information element120 comprises a specific SSID. Conversely, when the probe request is abroadcast probe request, the SSID information element 120 comprises anull SSID. The SSID information element 120 may be between 2 and 34octets.

The supported rates information element 122 is used to specify thetransmission rates supported by the station. Up to eight transmissionrates may be specified. The supported rates information element 122 maybe between 3 and 10 octets.

The frame body 104 of a probe request frame may also comprise one ormore of the following fields: a request information element 124, anextended supported rates information element 126 and a vendor specificinformation element 128.

The request information element 124 is used to request that anyresponding station include the requested information in their proberesponse. The request information element 124 typically comprises theelement IDs of the information requested listed in order of increasingelement ID.

The extended supported rates information element 126 is used when thestation supports more than 8 transmission rates. Specifically, where astation supports more than 8 transmission rates the additionaltransmission rates are listed in the extended supported ratesinformation element 126.

Each of the information elements, with the exception of thevendor-specific information element 128, has the format shown in FIG. 1c. Specifically, each information field (excluding the vendor-specificinformation field 128) comprises an element ID portion 130, a lengthportion 132 and an information portion 134. The element ID portion 130identifies the specific type of information field. The element IDs foreach of the information fields that may appear in a probe request areshown in Table 1. The length portion 132 specifies the length of theinformation element. The information portion 134 includes theinformation specific to the particular information element.

TABLE 1 Information Element Element ID Length (in octets) SSID 0 2 to34  Supported Rates 1 3 to 10  Request Information 10 2 to 256 ExtendedSupported Rates 50 3 to 257 Vendor-Specific 221 3 to 257

The vendor-specific information element 128 may be used to carryinformation not defined in the IEEE 802.11 standard and has the formatshown in FIG. 1d . Specifically, it comprises an element ID portion 136,a length portion 138, an Organizational Unique Identifier (OUI) portion140 and a vendor-specific content portion 142. The element ID portion136 and the length portion 138 correspond to the element ID portion 130and the length portion 132 of the generic information element asdescribed in reference to FIG. 1c . The OUI portion 140 includes a setof alphanumeric characters that uniquely identifies a vendor. The IEEEassigns OUIs to vendors. The OUI is sometimes referred to as the vendorID. The vendor-specific content portion 142 may contain any content andis only limited by the maximum frame size.

The inventor has identified that since: (1) probe requests may be sentby any Wi-Fi device (e.g. it is not limited to access points) withoutrequiring the Wi-Fi device to be fully connected to the Wi-Fi network,and (2) the vendor-specific information element 128 may contain any datain any format, the probe request may be used for transmitting smallamounts of data between Wi-Fi devices in a power-efficient manner.

In a first aspect the vendor-specific information element 128 is used totell a Wi-Fi station operating in a low power mode that it should“wake-up” from the low-power mode. The term “wake-up” is used herein tomean that the station changes operation from the low-power mode to ahigher power mode to enable the station to perform one or more actions.The higher power mode may be full power mode or a mode between fullpower mode and the low power mode. This enables a Wi-Fi station to enterinto a low-power mode (and thus conserve power) when it is not neededand quickly come back on-line when it is needed. In the low-power modethe Wi-Fi station is simply listening for Wi-Fi management frames. Thisaspect will be described in reference to FIGS. 2 to 6.

Reference is now made to FIG. 2 which illustrates a system 200 for usingthe vendor-specific information element 128 to cause a Wi-Fi station to“wake-up” from a low-power mode. The system 200 comprises a Wi-Fi accesspoint 202, a low-power Wi-Fi station 204, a Wi-Fi trigger station 206, aWi-Fi bridge station 208, and a non Wi-Fi trigger device 210.

The Wi-Fi access point 202 allows Wi-Fi stations (e.g. Wi-Fi stations204, 206 and 208) within range of the access point 202 to connect to acommon Wi-Fi network and communicate with each other via the commonWi-Fi network. The Wi-Fi access point 202 may also be connected toanother communication network 212, such as the Internet, which the Wi-Fistations 204, 206 and 208 may access via the Wi-Fi access point 202.

The Wi-Fi stations 204, 206 and 208 are computer-based devices thatcomprise a processor and a Wi-Fi module. The Wi-Fi module enables theWi-Fi station 204, 206 or 208 to wirelessly communicate with otherdevices using the IEEE 802.11 standard. The Wi-Fi stations 204, 206 and208 may be, but are not limited to, cameras, laptops, personalcomputers, tablet computers, mobile phones, radios, other audio devices,and smoke detectors.

The low-power Wi-Fi station 204 is a Wi-Fi station that that has theability to operate in a low-power mode where one or more modules of thestation 204 are suspended to conserve power. A module is considered tobe “suspended” if has been de-clocked, put into hibernation, paused,de-selected or otherwise put into a particular state to conserve power.The low-power mode may be a conventional Wi-Fi low power mode where theWi-Fi station agrees with the Wi-Fi access point 202 to enter alow-power mode. When the Wi-Fi station is operating in a conventionalWi-Fi low power mode the Wi-Fi access point 202 buffers any packets forthe Wi-Fi station for a number of beacon counts so the Wi-Fi station canoperate in a low-power mode during the buffering period. At the end ofthe buffering period the Wi-Fi station wakes up to stay connected to theWi-Fi network. However, it is not necessary for the low-power Wi-Fistation 204 described herein to be in a conventional Wi-Fi low powermode to be operating in a “low-power mode” as that term is used herein.Specifically, the low-power mode described herein does not require theWi-Fi station to wake up periodically to stay active on the network. Aslong as at least one module is suspended to conserve power the low-powerWi-Fi station will be understood as being in a low-power mode.

The low-power Wi-Fi station 204 may go into the low power mode whencertain predetermined conditions are met. The predetermined conditionsmay comprise, for example, but are not limited to, one or more of: apredetermined time has elapsed since the station has sent/received dataover/from the Wi-Fi network; the capacity of the battery for abattery-operated station has fallen below a predetermined threshold;according to a schedule (e.g. a low-power Wi-Fi station may beconfigured to go into a low-power mode at a certain time each day);based on an alarm state (e.g. armed or unarmed); detecting the presenceof a user (e.g. the Wi-Fi station may detect the presence of the uservia a key fob or similar device); and receiving notification that themaster device (e.g. a master device in a multi-room audio system) isgoing to sleep.

When the low-power Wi-Fi station 204 is operating in the low-power modethe station 204 listens to the 802.11 management packets for a specialprobe request frame. The special probe request frame comprises avendor-specific information element that comprises wake-up dataindicating the low-power Wi-Fi station 204 should wake-up. This type ofprobe request will be referred to herein as a wake-up probe request.Upon receiving a wake-up probe request, the low-power Wi-Fi station 204“wakes-up” from the low-power mode (e.g. it switches to a higher powermode by enabling one or more modules that were suspended to conservepower). The low-power Wi-Fi station 204 may then execute one or moreactions.

In some cases the wake-up probe request may be generated by a Wi-Fitrigger station 206 when one or more predetermined conditions are met. AWi-Fi trigger station 206 is a Wi-Fi station that is able to generatewake-up probe requests. For example, in a home security system the Wi-Fitrigger station 206 may be a motion detector or other sensor, and thelow-power Wi-Fi station 204 may be a video camera. The motion detectormay be configured to generate a wake-up probe request frame when itdetects motion (e.g. an intruder). Upon receiving the wake-up proberequest frame, the video camera may “wake-up” from the low-power modeand start recording video.

In other cases the wake-up probe request may be generated andtransmitted by a Wi-Fi bridge or hub station 208. A Wi-Fi bridge or hubstation 208 is a Wi-Fi station that has the ability to communicate usingat least one other communications protocol in addition to Wi-Fi (e.g.IEEE 802.11). The other communication protocol may be, for example,Bluetooth™, Digital Enhanced Cordless Telecommunications (DECT),ZigBee™, G.hn, Token Ring, Ethernet, Digital Living Network Alliance(DLNA), Universal Plug and Play (uPnP), or HomePlug.

The Wi-Fi bridge or hub station 208 may receive instructions to generatea wake-up probe request from a Non-Wi-Fi trigger device 210 usinganother communication protocol. A Non-Wi-Fi trigger device 210 is adevice that has the ability to detect when a wake-up probe requestshould be generated, but cannot communicate with the Wi-Fi network andthus cannot generate a wake-up probe request. The Non-Wi-Fi triggerdevice 210 may be unable to communicate with the Wi-Fi network becausefor example, it does not have a Wi-Fi module or it is not within rangeof the Wi-Fi network.

For example, in a home security system comprising a motion sensor and avideo camera, the motion sensor may not have Wi-Fi capability so it maybe connected to the Wi-Fi bridge or hub station 208 via a wiredconnection, such as Ethernet. The motion sensor then acts as theNon-Wi-Fi trigger device 210. Specifically, when the motion sensordetects motion (e.g. an intruder) it may be configured to notify theWi-Fi bridge or hub station 208. Upon receiving such a notification, theWi-Fi bridge or hub station 208 generates and transmits a wake-up proberequest frame. Upon receiving the wake-up probe request frame, the videocamera may “wake-up” and start recording video.

In some cases, the wake-up probe request may be in the form of abroadcast probe request (as described above in Reference to FIG. 1) sothat it will be processed by any Wi-Fi device within range. This formmay be used, for example, to transmit an urgent wake-up probe request(e.g. a wake-up probe request that is triggered by detection of a firealarm or the like). In other cases, the wake-up probe request may be inthe form of a directed probe request (as described above in Reference toFIG. 1) so that it will only be processed by Wi-Fi devices with the SSIDspecified in the probe request. This form may be used, for example, totarget the wake-up probe request to a specific SSID thus reducing thelikelihood that the wrong device (e.g. a device part of another BSS)will receive the wake-up probe request. An exemplary wake-up proberequest frame format will be described in reference to FIG. 6.

Reference is now made to FIG. 3 which illustrates a flow chart of amethod 300 for causing a low-power Wi-Fi station to “wake-up” from alow-power mode. At step 302, the low-power Wi-Fi station (e.g. Wi-Fistation 204) is operating in the low-power mode and listens for Wi-Fimanagement frames. At step 304 the low-power Wi-Fi station (e.g. Wi-Fistation 204) determines whether it has received a management frame. Ifthe low-power Wi-Fi station has not received a management frame then themethod proceeds back to step 302. If, however, the low-power Wi-Fistation has received a management frame then the method 300 proceeds tostep 306.

At step 306, the low-power Wi-Fi station determines whether the receivedmanagement frame is a probe request. Determining whether the managementframe is a probe request may comprise determining whether the frame bodyhas the format described in reference to FIG. 1b . If the low-powerWi-Fi station has determined that the received management frame is not aprobe request then the method 300 returns to step 302. If, however, thelow-power Wi-Fi station has determined that the received managementframe is a probe request then the method proceeds to step 308.

At step 308, the low-power Wi-Fi station determines whether the proberequest is a wake-up probe request. Determining whether the proberequest is a wake-up probe request may comprise determining whether theprobe request comprises a vendor-specific information element that has apredetermined format. If the low-power Wi-Fi station has determined thatthe probe request is not a wake-up probe request then the method 300returns to step 302. If, however, the low-power Wi-Fi station hasdetermined the probe request is a wake-up probe request then the method300 proceeds to step 310.

At step 310, the low-power Wi-Fi station “wakes-up” from the low-powermode. The low-power station may then perform one or more actions. Forexample, in some cases waking-up may involve generating and transmittinga special probe request in response to the wake-up probe request. Inother cases, waking up may comprise powering up or otherwise activatingone or more modules that were suspended to conserve power. For example,waking up may comprise enabling one or more modules, such as a TCP/IPmodule, to enable full Wi-Fi communication. In another example, wakingup may comprise enabling one or more modules, such as camera module, toenable non Wi-Fi capability.

In some cases the step(s) taken by the low-power Wi-Fi station to“wake-up” from the low-power mode may be based on the information in thewake-up probe request. Specifically, in some cases the wake-up proberequest may comprise action information that identifies an action or setof actions that are to be taken by the low-power Wi-Fi station when itwakes-up from the low-power-mode. For example, the wake-up probe requestmay specify that a low-power Wi-Fi camera is to start recording videowhen it wakes-up. In this example, waking up the low-power Wi-Fi stationmay comprise enabling a camera module.

In some cases, the low-power Wi-Fi station “wakes-up” from the low-powermode upon receiving a wake-up probe request only if it determines thatthe wake-up probe request is intended for the receiving low-power Wi-Fistation. For example, the wake-up probe request may comprise destinationinformation that identifies a particular low-power Wi-Fi station or agroup of Wi-Fi stations. For example, the destination information maycomprise a device type that tells all stations of that device type thatthat the wake-up packet is intended for them; or a serial number or MACaddress that tells a particular station that the wake-up packet isintended for it. Accordingly, in these cases the low-power Wi-Fi stationmay be configured to analyze the destination information in the wake-upprobe request prior to waking up from the low-power mode.

Reference is now made to FIG. 4 which illustrates a flow chart of anexemplary method 400 for a trigger Wi-Fi station to generate andtransmit a wake-up probe request. At step 402, the trigger Wi-Fi station(e.g. trigger Wi-Fi station 206) monitors one or more conditions. Atstep 404, the trigger Wi-Fi station determines whether at least onepredetermined condition is met. As described above in reference to FIG.2, where the trigger Wi-Fi station is a motion sensor in a securitysystem the predetermined condition may be when the motion sensor detectsmotion. If the trigger Wi-Fi station determines that none of thepredetermined conditions are met, then the method proceeds back to step402. If, however, the trigger Wi-Fi station determines that at least onepredetermined condition is met, the method 400 proceeds to step 406. Atstep 406, the trigger Wi-Fi station generates wake-up data that conformsto a predetermined format (e.g. the format described in reference toFIG. 6). At step 408, the trigger Wi-Fi station inserts the wake-up datain the vendor-specific element of a probe request frame to generate awake-up probe request frame. At step 410, the trigger Wi-Fi station thenwirelessly transmits the wake-up probe request frame.

Reference is now made to FIG. 5 which illustrates a flow chart of amethod 500 for a non-Wi-Fi trigger device 210 to trigger the generationand transmission of a wake-up probe request. At step 502, the non-Wi-Fitrigger device (e.g. non-Wi-Fi trigger device 210) monitors one or moreconditions. At step 502, the non-Wi-Fi trigger station determineswhether at least one predetermined condition as met. As described abovein reference to FIG. 2, where the non-Wi-Fi trigger device is a motionsensor in a security system, the predetermined condition may, forexample, be met when the motion sensor detects motion. If the non-Wi-Fitrigger device determines that none of the predetermined conditions aremet, then the method proceeds back to step 502. If, however, the nonWi-Fi trigger device determines that at least one predeterminedcondition is met, the method 500 proceeds to step 506. At step 506, thenon Wi-Fi device notifies a Wi-Fi bridge or hub station (e.g. Wi-Fibridge or hub station 208) that the predetermined condition has beenmet. The notification may be sent from the non Wi-Fi device to the Wi-Fibridge or hub station using a protocol other than Wi-Fi (IEEE 802.11),such as Bluetooth ZigBee™ or Ethernet. The method 500, then proceeds tostep 508. At step 508, the Wi-Fi bridge or hub station generates wake-updata that conforms to a predetermined format (e.g. the format describedin reference to FIG. 6). At step 510, the Wi-Fi bridge or hub stationinserts the wake-up data in the vendor-specific element of a proberequest frame to generate a wake-up probe request frame. At step 512,the Wi-Fi bridge or hub station then wirelessly transmits the wake-upprobe request frame.

Reference is now made to FIG. 6 which illustrates an exemplary formatfor the vendor-specific information element 128 of a probe request. Asdescribed in reference to FIG. 1d , the vendor-specific informationelement 128 comprises a one octet element ID portion 136, a one octetlength portion 138, a one octet OUI portion 140 and a variable lengthvendor-specific content portion 142. The vendor specific content portion142 may comprise a header portion 602, an application type portion 604,a length portion 606, a payload portion 608, a sequence portion 610 anda checksum portion 612.

The header portion 602 may be used to identify the probe request as awake-up probe request. This allows Wi-Fi stations to easily and quicklyidentify wake-up probe request packets. For example, the header portion602 may include a particular code (e.g. 0x9000) to indicate that it is awake-up probe request. Conversely, the header portion 602 may includeanother code (e.g. 0x8000) to indicate that it is a status probe request(status probe requests are described below in relation to FIGS. 7-10).

The application type portion 604 may identify the device type that thepacket is intended for. For example, the application type portion 604may be used to identify that the frame is intended for a camera or atelevision.

The length portion 606 is used to specify the length of the payloadportion 608 since the payload portion 608 may have a variable length.

The payload portion 608 is where the wake-up data itself is inserted. Insome cases the payload portion 608 may comprise a list of command codes,where each command code is two octets and specifies an action that thereceiving station should take. Typically, each wake-up probe requestcomprises at least a wake-up command code. The wake-up command code maybe followed by one or more additional command codes specifying an actionor actions that the receiving station is to execute upon waking up.Table 2 provides an example list of commands/actions and theirassociated codes.

TABLE 2 Command/Action Value Wake-Up 0x0001 Record Video 0x0002 GenerateAlert 0x0003 Broadcast Audio 0x0004

It will be evident to a person of skill in the art that the listprovided in Table 2 is exemplary and that the methods and systemsdescribed herein may be implemented with more or fewer command codes orwith a different set of command codes.

The sequence portion 610 may be used to identify a sequence number. Thesequence number may be used to enable a large packet to be split intoseveral packets. For example, a sequence number of zero may denote thatthere are no further packets related to this packet and a sequencenumber of greater than zero may denote that there are more packets thatrelate to this packet. Accordingly, the Wi-Fi station generating thewake-up probe request may generate the sequence number based on the sizeof the data to transmit.

The checksum portion 612 may be used to insert a checksum value toensure that the vendor specific content portion 142 has been receivedcorrectly. As is known to those of skill in the art a checksum value isa value that is generated from at least a portion of data to enabledetection of any errors that may have occurred during transmission. Oncethe data is received at the other end its accuracy can be checked byre-computing the checksum from the received data and comparing it to thechecksum in the checksum portion 612. Any suitable checksum algorithmmay be used to generate the checksum data, including, but not limitedto, parity byte, parity word, modular sum and position dependentchecksum. In some cases the vendor specific content portion 142 may alsocomprise an authentication portion (e.g. an authentication token) toauthenticate the sender to the recipient.

The methods and systems described in reference to FIGS. 2 to 6 may beused, for example, in a security system. For example, as describedabove, the system may comprise a motion sensor (trigger Wi-Fi station206), a video camera (low-power Wi-Fi station 204) and an alarmgeneration device (low-power Wi-Fi station 204). The alarm generationdevice and the video camera may go into a low-power mode until themotion sensor detects motion. Once the motion sensor detects motion itmay generate a wake-up probe request for the alarm generation device andvideo camera. Upon receiving the wake-up probe request the video cameramay, for example, wake-up and start recording video. Upon receiving thewake-up probe request the alarm generation device may, for example,generate an alarm.

The methods and systems described in reference to FIGS. 2 to 6 may alsobe used, for example, in a multi-room audio system where audio followsthe user from room to room. For example, each room may comprise at leastone Wi-Fi motion sensor (trigger Wi-Fi station 206) and at least onebattery operated Wi-Fi audio device (low-power Wi-Fi station(s) 204).The battery operated audio devices may be able to go into a low-powermode until the user enters the room that they are in. Specifically, oncea particular motion sensor detects motion, it may generate a wake-upprobe request for the battery operated audio device(s) in its room. Uponreceiving the wake-up probe request, the audio device(s) powers fully onto enable broadcasting of audio.

The methods and systems described in reference to FIGS. 2 to 6 may alsobe used, for example, in a multi-room video and/or audio system toenable a remote control to turn on or enable devices in any room. Forexample, each room may comprise a Wi-Fi enabled TV, audio device,DVD-player and/or a radio (low-power Wi-Fi station(s) 204) that has theability to operate in a low-power mode when not in use to save power.The user then has a Wi-Fi enabled universal remote control (triggerWi-Fi station 206). When the user enters a room, the user may press asingle button on the universal remote control to wake-up all of thedevices in that room. For example, the single button may cause theuniversal remote control to generate and transmit a wake-up proberequest frame which causes all of the devices in the room to wake-upfrom their low-power mode.

In a second aspect the vendor-specific information element 128 is usedby a Wi-Fi station to transmit status data.

Reference is now made to FIG. 7 which illustrates a system 700 whereinWi-Fi stations use the vendor-specific information element 128 totransmit status data. The system 700 comprises a Wi-Fi access point 702,a status generating Wi-Fi station 704, a multi-function status receivingWi-Fi station 706, a dedicated status receiving Wi-Fi station 708, aWi-Fi bridge or hub station 710, and a Non-Wi-Fi device 712.

The Wi-Fi access point 702, like the Wi-Fi access point 202 of FIG. 2,allows Wi-Fi stations (e.g. Wi-Fi stations 704, 706, 708 and 710) withinrange of the access point 702 to connect to a common Wi-Fi network andcommunicate with each other via the common Wi-Fi network. The Wi-Fiaccess point 702 may also be connected to another communication network714, such as the Internet, which the Wi-Fi stations 704, 706, 708 and710 may access via the Wi-Fi access point 702.

The Wi-Fi stations 704, 706, 708 and 710, like the Wi-Fi stations 204,206 and 208 of FIG. 2, are computer-based devices that comprise aprocessor and a Wi-Fi module. The Wi-Fi module enables the Wi-Fi stationto wirelessly communicate with other devices using the IEEE 802.11standard. The wireless stations 704, 706, 708 and 710 may be, but arenot limited to, cameras, laptops, personal computers, tablet computers,mobile phones, radios, other audio devices, and smoke detectors.

The status generating Wi-Fi station 704 is configured to generate andtransmit a special probe request frame when one or more predeterminedconditions are met. The special probe request frame comprises avendor-specific information element in a predetermined format thatcomprises status data. This type of special probe request will bereferred to herein as a status probe request. A status probe request maybe used, for example, to indicate that the station is currentlyexperiencing a problem (e.g. low battery) or that the station previouslyexperienced a problem (e.g. was unable to connect to the Wi-Fi for aperiod of time).

Examples of predetermined conditions which may trigger a status proberequest include, but are not limited to: the station has been unable toreceive and/or transmit data over the Wi-Fi network for a predeterminedperiod of time; loss of authentication with the Wi-Fi network; detectionof an unknown Wi-Fi station on the Wi-Fi network; and the battery levelfor a battery-operated station has dropped below a predeterminedthreshold.

Status data may be any data about the status generating Wi-Fi station704 that may be used by another device. Examples of status data that maybe included in a status probe request include, but are not limited to:data about how long the station was unable to receive and/or transmitdata over the Wi-Fi data network (and optionally other parameters thatallow a diagnosis of the problem); data indicating system performance(e.g. quality or accuracy of a system server, such as a time server, amedia server or an audio server); data indicating a Wi-Fi station'slevel of synchronization; data indicating synchronization with a mastertime server (e.g. in some cases (e.g. multi-room audio) slave stationsmay try to synchronize with a master station, the time synchronizationdata provided in the status probe request may then be used to makedecisions on who is following the master etc.); and data indicating thatthe battery is low (and optionally the current level of the battery).

Using a status probe request frame to transmit status data allows thestatus generating Wi-Fi station 704 to provide status data to otherdevices within Wi-Fi range of the station 704 without requiring thestation 704 to be fully connected to the Wi-Fi network (e.g. the station704 does not require an IP address). This may be particularly useful,for example, in situations where a battery-operated station does nothave enough energy to bring up its TCP/IP stack (thus it cannotconnect/maintain its Wi-Fi connection), but wishes to transmit statusinformation (e.g. a battery low message).

In some cases, status probe requests may be received and processed by amulti-function status receiving Wi-Fi station 706. A multi-functionstatus receiving Wi-Fi station 706 is a Wi-Fi station that performsother functions in addition to processing status probe requests. Forexample, the multi-function status receiving Wi-Fi station 706 may havethe ability to record video, detect motion, and/or broadcast audio; inaddition to having the ability to process status probe requests. Themulti-function status receiving Wi-Fi station 706 may be configured toprocess the status probe request directly. For example, where both thestatus generating Wi-Fi station 704 and the multi-function statusreceiving Wi-Fi station 706 have the same capabilities (e.g. bothstations have the ability to record video), upon receiving a statusprobe request from the status generating Wi-Fi station 704 indicatingthat the battery level is low, the multi-function status receiving Wi-Fistation 706 may “take-over” from the status generating Wi-Fi station 706(e.g. the multi-function status receiving Wi-Fi station 706 may startrecording video). In another example, if a station receives a statusprobe request indicating that the Wi-Fi network is experiencingproblems, the multi-function status receiving Wi-Fi station 706 mayenter into a low-power mode to conserve power.

Alternatively the multi-function status receiving Wi-Fi station 706 maybe configured to simply forward at least a portion of the status proberequest to another device, such as a remote server 716, that willprocess the status data. Whether the multi-function status receivingWi-Fi station 706 forwards the status probe request or processes thestatus probe request may depend on the type of status data in the statusprobe request. For example, in some cases the multi-function statusreceiving Wi-Fi station 706 may be able to take action, and in othercases the multi-function status receiving Wi-Fi station 706 may only beable to forward at least a portion of the status probe request toanother device for further processing.

In other cases, status probe requests may be received and processed by adedicated status receiving Wi-Fi station 708. A dedicated statusreceiving Wi-Fi station 708 is a Wi-Fi station whose main purpose is tohandle and process status probe requests. The dedicated status receivingWi-Fi station 708 may take one or more actions upon receiving a statusprobe request. For example, upon receiving a status probe requestindicating low battery the dedicated status receiving Wi-Fi station 708may send a message to the owner or administrator of the transmittingstation that the battery is low. The message may be sent using anysuitable communication means, such as email, SMS message or voicemessage. Alternatively, the dedicated status receiving Wi-Fi station 708may simply forward at least a portion of the status probe request toanother device, such as remote server 716.

In other cases, status probe requests may be received and processed by aWi-Fi bridge or hub station 710. A Wi-Fi bridge or hub station 710 is aWi-Fi station that has the ability to communicate using at least oneother communication protocol in addition to Wi-Fi (e.g. IEEE 802.11).The other communication protocol may be, for example, Bluetooth™,Digital Enhanced Cordless Telecommunications (DECT), ZigBee™, G.hn,Token Ring, Ethernet, Digital Living Network Alliance (DLNA), UniversalPlug and Play (uPnP), or HomePlug. Upon receiving a status proberequest, the bridge or hub Wi-Fi station 710 may be configured toprovide at least a portion of the status probe request (e.g. the statusdata) to a Non Wi-Fi device 712 via one of the other protocols supportedby the bridge or hub Wi-Fi station.

An example of a non Wi-Fi device is a wireless power switch which may beusing a different communications protocol or a different RF (radiofrequency) channel. The wireless power switch may be configured toswitch off if the user is no longer present (or conversely switch on ifthe user is present). Accordingly, one Wi-Fi station may be configuredto detect the presence or lack of presence of a user (e.g. via a key fobor similar device). The Wi-Fi station may then transmit a status proberequest indicating the status of the user (e.g. present or not present).The status probe request may be received by a bridge or hub Wi-Fistation who forwards the status probe request to the wireless powerswitch using the other communications protocol. The wireless powerswitch may then make a decision on whether to turn on/off based on theinformation in the status probe request.

Reference is now made to FIG. 8, which illustrates a flow chart of amethod 800 for a status generating Wi-Fi station to generate a statusprobe request. At step 802, the status generating Wi-Fi station (e.g.status generating Wi-Fi station 704) monitors one or more conditions. Atstep 804, the status generating Wi-Fi station determines whether atleast one predetermined condition is met. As described above inreference to FIG. 7, where the status generating Wi-Fi station isbattery-operated the predetermined condition may be when the batterylevel falls below a predetermined threshold. If the status generatingWi-Fi station determines that none of the predetermined conditions aremet, then the method proceeds back to step 802. If, however, the statusgenerating Wi-Fi station determines that at least one predeterminedcondition is met, the method 800 proceeds to step 806. At step 806, thestatus generating Wi-Fi station generates status data in accordance witha predetermined format. The status data may be based on thepredetermined conditions that were met in step 804. For example, if thepredetermined condition is that the battery level has dropped, thestatus data may contain data indicating that the battery power is low.Different status data may be generated when a different predeterminedcondition is met. At step 808, the status generating Wi-Fi stationinserts the status data in the vendor-specific element of a proberequest frame to generate a status probe request frame. At step 810, thestatus generating Wi-Fi station then wirelessly transmits the statusprobe request frame.

Reference is now made to FIG. 9, which illustrates a flow chart of anexemplary method 900 for processing a status probe request. At step 902,a status receiving Wi-Fi station (e.g. multi-function status receivingWi-Fi station 706, dedicated status receiving Wi-Fi station 708, orWi-Fi bridge or hub station 710) receives a probe request. At step 904,the status receiving Wi-Fi station determines whether the probe requestis a status probe request. Determining whether the probe request is astatus probe request may comprise determining if the probe requestcomprises a vendor-specific information element that comprises statusdata in a predetermined format. If the status receiving Wi-Fi stationdetermines that the probe request is not a status probe request, thenthe method ends. If, however, the status receiving Wi-Fi stationdetermines that the probe request is a status probe request then themethod 900 proceeds to step 906.

At step 906, the status receiving Wi-Fi station determines whether thestatus probe request may be processed by the status receiving Wi-Fidevice. Determining whether the status probe request may be processed bythe status receiving Wi-Fi device may comprise analyzing thevendor-specific element of the probe request to determine the type ofstatus probe request. For example, the status receiving Wi-Fi stationmay be able to process requests from some types of Wi-Fi stations, butnot others. If the status-receiving Wi-Fi station determines that itcannot process this particular status probe request then the methodproceeds to step 910. If however, the status receiving Wi-Fi stationdetermines that it has the ability to process this particular statusprobe request then the method proceeds to step 908.

At step 908, the status receiving Wi-Fi station processes the statusprobe request. Processing the status probe request may compriseexecuting one or more actions based on the type of status probe request.The one or more actions may comprise, for example, but are not limitedto: notifying an owner (via e-mail, SMS or any other suitable means);taking over the sending station's duties; or any combination thereof.Once the status probe request frame has been processed, the method 900ends.

At step 910, the status receiving Wi-Fi station may forward at least aportion of the status probe request to another device. The other devicemay, for example, be another Wi-Fi station, a remote server, or a localdevice that supports another protocol. Once the status probe request isforwarded, the method 900 ends.

Reference is now made to FIG. 10 which illustrates an exemplary formatfor the vendor-specific information element 128 of a status proberequest. As described in reference to FIG. 1d , the vendor-specificinformation element 128 comprises a one octet element ID portion 136, aone octet length portion 138, a one octet OUI portion 140 and a variablelength vendor-specific content portion 142. Similar to the wake-up proberequest described in reference to FIG. 6, the vendor specific contentportion 142 of a status probe request may comprise a header portion1002, an application type portion 1004, a length portion 1006, a payloadportion 1008, and a sequence portion 1010. However, in contrast to thewake-up probe request, the status probe request shown in FIG. 10 doesnot comprise a checksum portion. Instead, the status probe request ofFIG. 10 comprises a timestamp portion 1012 that may denote the time ofthe status probe request and/or the time when the next status proberequest is due.

In some cases, the only other difference between the format of a wake-upprobe request and the format of a status probe request is the format ofthe payload portion 1008. For example, instead of the payload portioncomprising a list of command codes; the payload portion 1008 maycomprise a list of status codes where each status code indicates aparticular status. Table 3 provides an example list of statuses andtheir associated codes. In some cases one or more of the status commandcodes may be followed by a specific qualifier. For example, a lowbattery status may be followed by a numerical value indicating thepercentage of battery remaining. Whether or not there is any qualifyinginformation may depend on the particular status. Furthermore, the sizeof the qualifier field may also depend on the particular status. Forexample, some qualifiers may be two octets in size where others may befour octets in size.

TABLE 3 Status Value Qualifier Low Battery 0x0001 % of battery remainingUnable to Communicate with 0x0002 Time station was Wi-Fi data networkunable to communicate with Wi-Fi data network Synchronization Level with0x0003 Master Good Synchronization Level with 0x0004 Master Poor

It will be evident to a person of skill in the art that the listprovided in Table 3 is exemplary and that the methods and systemsdescribed herein may be implemented with more or fewer status codes orwith a different set of status codes.

The methods and systems described in reference to FIGS. 7 to 10 may beused, for example, by smoke alarms to indicate a low-battery, or windowor door sensors to indicate a window or door is open. Using the methodsand systems described herein to transmit this type of information allowsthe devices (smoke alarms, sensors) to transmit data in a low-power wayusing a standard protocol that is used in most homes and offices makingit easy to integrate with existing devices and infrastructure.

In a third aspect the vendor-specific information element 128 is used bya Wi-Fi station to transmit wake-up data (as described in references toFIGS. 2 to 6) and status data (as described in reference to FIGS. 7 to10) in the same probe request frame. For example, in this aspect asingle Wi-Fi station may perform the functions of the status generatingWi-Fi station of FIG. 7 and the trigger Wi-Fi station of FIG. 2.Specifically, when this single Wi-Fi station detects one or morepredetermined conditions are met, it may generate both status data andwake-up data and then insert the status data and the wake-up data intothe vendor-specific information element 128 of a probe request frame togenerate a status wake-up probe request frame. The single Wi-Fi stationthen wirelessly transmits the status wake-up probe request frame.

For example, the single Wi-Fi station of this aspect may be a motionsensor that upon detecting motion generates wake-up data telling anotherstation or stations (e.g. a video camera) to wake-up and status dataindicating that there is an intruder. In response to the wake-up data, alow-power Wi-Fi station receiving the status wake-up probe request framewakes-up from the low-power mode, and in response to the status data,the low-power Wi-Fi station performs one or more actions. For example,where the low-power Wi-Fi station is a video camera, the low-power Wi-Fistation may begin recording video in response to the status data.

The term ‘processor’ and ‘computer’ are used herein to refer to anydevice with processing capability such that it can execute instructions.Those skilled in the art will realize that such processing capabilitiesare incorporated into many different devices and therefore the term‘computer’ includes set top boxes, media players, digital radios, PCs,servers, mobile telephones, personal digital assistants and many otherdevices.

Those skilled in the art will realize that storage devices utilized tostore program instructions can be distributed across a network. Forexample, a remote computer may store an example of the process describedas software. A local or terminal computer may access the remote computerand download a part or all of the software to run the program.Alternatively, the local computer may download pieces of the software asneeded, or execute some software instructions at the local terminal andsome at the remote computer (or computer network). Those skilled in theart will also realize that by utilizing conventional techniques known tothose skilled in the art that all, or a portion of the softwareinstructions may be carried out by a dedicated circuit, such as a DSP,programmable logic array, or the like.

Memories storing machine executable data for use in implementingdisclosed aspects can be non-transitory media. Non-transitory media canbe volatile or non-volatile. Examples of volatile non-transitory mediainclude semiconductor-based memory, such as SRAM or DRAM. Examples oftechnologies that can be used to implement non-volatile memory includeoptical and magnetic memory technologies, flash memory, phase changememory, resistive RAM.

A particular reference to “logic” refers to structure that performs afunction or functions. An example of logic includes circuitry that isarranged to perform those function(s). For example, such circuitry mayinclude transistors and/or other hardware elements available in amanufacturing process. Such transistors and/or other elements may beused to form circuitry or structures that implement and/or containmemory, such as registers, flip flops, or latches, logical operators,such as Boolean operations, mathematical operators, such as adders,multipliers, or shifters, and interconnect, by way of example. Suchelements may be provided as custom circuits or standard cell libraries,macros, or at other levels of abstraction. Such elements may beinterconnected in a specific arrangement. Logic may include circuitrythat is fixed function and circuitry can be programmed to perform afunction or functions; such programming may be provided from a firmwareor software update or control mechanism. Logic identified to perform onefunction may also include logic that implements a constituent functionor sub-process. In an example, hardware logic has circuitry thatimplements a fixed function operation, or operations, state machine orprocess.

The term ‘upon’ is used herein to refer to an action or operation whichis performed in response to a trigger action, signal etc. It will beappreciated that the response may be an attenuated response and so theterm ‘upon’ is not limited to an immediate temporal relationship betweenthe trigger and the resultant action.

Any range or device value given herein may be extended or alteredwithout losing the effect sought, as will be apparent to the skilledperson.

It will be understood that the benefits and advantages described abovemay relate to one embodiment or may relate to several embodiments. Theembodiments are not limited to those that solve any or all of the statedproblems or those that have any or all of the stated benefits andadvantages.

Any reference to ‘an’ item refers to one or more of those items. Theterm ‘comprising’ is used herein to mean including the method blocks orelements identified, but that such blocks or elements do not comprise anexclusive list and an apparatus may contain additional blocks orelements and a method may contain additional operations or elements.Furthermore, the blocks, elements and operations are themselves notimpliedly closed.

The steps of the methods described herein may be carried out in anysuitable order, or simultaneously where appropriate. Additionally,individual blocks may be deleted from any of the methods withoutdeparting from the spirit and scope of the subject matter describedherein. Aspects of any of the examples described above may be combinedwith aspects of any of the other examples described to form furtherexamples without losing the effect sought. Where elements of the figuresare shown connected by arrows, it will be appreciated that these arrowsshow just one example flow of communications (including data and controlmessages) between elements. The flow between elements may be in eitherdirection or in both directions.

It will be understood that the above description of a preferredembodiment is given by way of example only and that variousmodifications may be made by those skilled in the art. Although variousembodiments have been described above with a certain degree ofparticularity, or with reference to one or more individual embodiments,those skilled in the art could make numerous alterations to thedisclosed embodiments without departing from the spirit or scope of thisinvention.

What is claimed is:
 1. A method to wirelessly transmit data, the methodcomprising: generating at a first Wi-Fi station data to be transmittedto another Wi-Fi station, the data comprising at least one of statusdata and wake-up data; inserting at the first Wi-Fi station thegenerated data in a vendor-specific information element of a Wi-Fi proberequest frame; and wirelessly transmitting at the first Wi-Fi stationthe Wi-Fi probe request frame; wherein at least one of the first Wi-Fistation and the other Wi-Fi station is operating in a low-power mode inwhich at least one module in the Wi-Fi station is suspended to conservepower.
 2. The method according to claim 1, wherein the wake-up data isarranged to cause the other Wi-Fi station to wake-up from a low-powermode.
 3. The method according to claim 1, further comprising:determining at the first Wi-Fi station whether one or more predeterminedconditions are met; and wherein the first Wi-Fi station generates thedata to be transmitted if at least one predetermined condition is met.4. The method according to claim 1, wherein the Wi-Fi probe requestframe is a broadcast probe request frame.
 5. The method according toclaim 1, wherein the Wi-Fi probe request frame comprises the wake-updata and the status data.
 6. A system to wirelessly transmit data, thesystem comprising a first Wi-Fi station and the first Wi-Fi stationcomprising: a processor configured to: operate the first Wi-Fi stationin a low-power mode in which at least one module in the first Wi-Fistation is suspended to conserve power; generate data to be transmittedto another Wi-Fi station, the data comprising at least one of statusdata and wake-up data, and insert the generated data in avendor-specific information element of a Wi-Fi probe request frame; anda Wi-Fi module configured to wirelessly transmit the Wi-Fi probe requestframe.
 7. The system according to claim 6, wherein the wake-up data isarranged to cause the other Wi-Fi station to wake-up from a low-powermode.
 8. The system according to claim 6, further comprising the otherWi-Fi station configured to: receive the Wi-Fi probe request frame; andin response to receiving the Wi-Fi probe request frame, execute one ormore actions.
 9. The system according to claim 8, wherein the otherWi-Fi station is operating in a low-power mode when it receives theWi-Fi probe request frame comprising the wake-up data and the one ormore actions executed by the other Wi-Fi station comprises waking up theother Wi-Fi station from the low-power mode.
 10. The system according toclaim 6, further comprising a non-Wi-Fi device configured to: determinewhether one or more predetermined conditions are met; and if at leastone predetermined condition is met, transmit a notification from thenon-Wi-Fi device to the first Wi-Fi station that at least onepredetermined condition is met; wherein the first Wi-Fi stationgenerates the data to be transmitted in response to receiving thenotification from the non-Wi-Fi device that at least one predeterminedcondition is met.
 11. The system according to claim 10, wherein thenotification is transmitted using a protocol other than Wi-Fi.
 12. Thesystem according to claim 6, wherein the Wi-Fi probe request frame is abroadcast probe request frame.
 13. The system according to claim 6,wherein the Wi-Fi probe request frame comprises the wake-up data and thestatus data.
 14. A Wi-Fi station comprising: a Wi-Fi module configuredto wirelessly receive a Wi-Fi probe request frame from another Wi-Fistation while the Wi-Fi station is operating in a low power-mode inwhich at least one module in the Wi-Fi station is suspended to conservepower, the Wi-Fi probe request frame comprising at least one of statusdata and wake-up data in a vendor-specific information element of theWi-Fi probe request frame; and a processor configured to: execute one ormore actions in response to receiving the Wi-Fi probe request frame. 15.The Wi-Fi station according to claim 14, wherein the one or more actionsexecuted by the processor comprises: determining whether the receivedWi-Fi probe request frame comprises a vendor-specific informationelement comprising wake-up data; and if the Wi-Fi probe request framecomprises the vendor specific information element comprising wake-updata, waking-up the Wi-Fi station from the low-power mode.
 16. The Wi-Fistation according to claim 15, wherein operating the Wi-Fi station inthe low-power mode comprises suspending at least a portion of the Wi-Fistation and waking-up the Wi-Fi station from the low-power modecomprises enabling the at least a portion of the Wi-Fi station.
 17. TheWi-Fi station according to claim 14, wherein the processor is furtherconfigured to determine if one or more predetermined conditions are metand if at least one predetermined condition is met, operate the Wi-Fidevice in the low-power mode.
 18. The Wi-Fi station according to claim14, wherein the Wi-Fi probe request frame comprises the status data andthe one or more actions executed by the processor comprises forwardingat least a portion of the Wi-Fi probe request frame to another device.19. The Wi-Fi station according to claim 14, wherein the Wi-Fi proberequest frame comprises the status data and the one or more actionsexecuted by the processor comprises processing the Wi-Fi probe requestframe.